Oil pump



Feb. 9, 1937. b. "GREG'G 2,070,203

011. PUMP Filed Nov. 5, 1934 BY xfa/Lw?? ATTORNEY.

Patented Feb. 9, 1937 UNITED STATES PATENT OFFICE Eclipse AviationCorporation, East Orange,

N. J., a corporation of New Jersey 'Application November 5, 1934, SerialNo. 751,604

8 Claims.

This invention relates to pumps and more particularly to reciprocatingpumps that are suitable for pumping small quantities of liquid.

An object of the invention is to provide a uid 5 pump which will supplysmall quantities of fluid in a predetermined amount at each stroke ofthe piston.

Another object of the invention is to providea reciprocating fluid pumpin which the amount of fluid that is pumped may be readily varied.

Another object of the invention is to provide a reciprocating uid pumpin which the amount of fluid pumped may be varied without changing thepump speed.

Another object of the invention is to provide a reciprocating uid pumpin which the pumping capacity may be varied by changing the angularposition of the piston with respect to its recipro cal position.

0 Other objects of the invention will be apparent from the followingdescription in connection with which certain embodiments of theinvention have been shown in the accompanying drawing in which:

Fig. 1 is a side elevation partly in section of a vane type air pumphaving an oil pump constructed in accordance with the invention;

Fig. 2 is an end view of the oil pump shown in Fig. 1';

Fig. 3 is a view partly in section, the sectional portion being taken online 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on line 44 of Fig. 1;

Fig. 5 is a sectional view taken on line 5-5 of 5 Fig. 1;

Fig. 6 is an enlarged View showing a modified form of cylinderconstruction; and

Fig. 7 is an enlarged end view of the oil pump piston, taken along line1-1 of Fig. 4.

J Referring to the drawing, the air pump upon which the improved oilpump is mounted is indicated generally at I0 and is of well knownconstruction, having a rotor I! eccentrically mounted in casing I2 bybearing'l3. Slidable vanes I4 are mounted in the rotor, and the inletandoutlet ports to the air pump are shown at I6 and I1. respectively,(Fig. 5). Inlet port I6 is connected to the atmosphere through a coredpassageway y 20 that is formed in the oiler head by means of l pipe I8,and the outlet is connected through a similar passage, not shown, todischarge pipe I3. In air pumps for certain purposes it is desirable tosupply lubricant thereto in measured quantities so that the minimumamount of lubricant i is supplied to adequately lubricate the same. An

over-supply may allow some of the oil to enter the outlet pipe and bedetrimental to the functioning of devices that are operated by the airpump. For example, if the air pump be used to inate rubber articles itis very desirable to reduce the oil supply to a minimum and thus preventdeterioration of the rubber from the excess oil that is passed throughthe outlet line.

The oil pump embodying the present invention is secured to thel casingI2 by screws 2| and is driven by shaft 22 having a squared end 24 whichis mounted within a squared opening 25 formed in the rotor I I. Shaft 22is rotatably mounted in the oil pump housing26 by bearings 21 and 28 andis provided with a worm 29 in mesh with the worm wheel 3|. A bushing 32forming the oil pump cylinder is pressed within the casing 26 withinwhich is mounted the reciprocating piston 33, the outer end of thecylinder being closed by a threaded plug 34 having a cylindricalprojection 36 projecting within the cylinder to determine the clearancevolume of the pump, it being apparent that plug 34 can be readilychanged and another one substituted to provide any clearance that isdesired. Cylinder 32 is preferably positioned horizontally and connectedwith compartment 31 by an oil inlet port 38, oil being supplied to thecompartment 31 by any suitable means, such as a separate pump (notshown) by means of oil supply pipe 4I. A metering disc 42 is provided inthe oil supply line for regulation of the quantity of oil delivered, butthis is not essential. It is desirable, however, to keep an adequatesupply of oil in the reservoir 31 so that inlet 38 may be covered at alltimes. The piston 33 is provided with a pin 44 which is slldably mountedin a groove 46 formed in the interior of worm wheel 3|. A member 41 issecured to piston 33 by any desired means, such as rivet 48, andcontains a groove 49 formed by two parallel cam surfaces 5I and 52. Apin 53 is secured to sleeve 54 and projects within the groove 49. Sleeve54 is rotatable in the housing and secured in any desired angularposition by screw 56. Screw slot 51 is provided for angular adjustmentof the sleeve by any suitable tool. Sleeve 54 surrounds the cam groove49 and is provided with a reduced portion 59 forming a bearing vfor thepiston 33. The outlet port 6I of the cylinder is in communication withthe air inlet compartment 20 which communicates with the air'pump I0.The pump inlet port 38 and outlet port 6I are controlled by a slot 63formed in piston 33 which is in communicat-cn with the cylinder by anend slot 64.

In the operation of the pump. compartment 31 is supplied with oil fromany suitable source and inlet port 38 is submerged. Rotation of shaft 22causes piston 33 to rotate and during the rotation thereof, the pistonis also reciprocated bymeans of the pin 53 and the cam slot 49. It willbe apparent that the piston is shown in its extreme position toward theright and further rotation'will cause it to move toward the left, asviewed in Fig. 4. It is assumed that a charge of oil has been drawn intothe cylinder during a previous portion of the cycle, and it is apparentthat the movement of the piston toward the left will force oil from thecylinder through the slots 64 and 63 into the air inlet chamber 20 fromwhich it will be delivered to the air pump by port I6 for lubricationthereof.

In the embodiment shown in Fig. 4 the stroke is substantially equal tothe width of the ports 6| and 38 and the slot 33 extends oversubstantially one-half of the piston circumference. The sleeve 54 is'shown in an adjusted position to deliver onehalf the cylinderdisplacement during one pump cycle. Rotation of sleeve 54 through 90degrees in either direction from the position shown will cause the pumptodeliver its full cylinder displacement during each cycle, and rotationof the sleeve through degrees will reducethe delivery to substantialyone-half the cylinder displacement.

The cycle of operation of the pump with the sleeve 54 in the positionshown is as follows:

The first quarter of revolution moves the piston one-half stroke towardthe left and discharges one-half the cylinder displacement to air'chamber 20.

The second quarter of revolution moves they piston to its extremeposition toward the left, but

during this portion of the stroke the inlet port 38 is uncovered by slot63 and the exhaust port 6I is closed, therefore any oil remaining in thecylinder is returned to chamber 31.

The third quarter of revolution moves the piston one-half stroke towardthe right and draws oil into the cylinder from the inlet chamber 31through port 38.

'I'he fourth quarter revolution moves the piston to its extreme rightposition and suction is applied to the exhaust port 6l, but no oil isdrawn into the cylinder as chamber 20 is the air intake chamber of theair pump and is much larger than the displacement-space of the oil pump,therefore there is no oil adjacent the port 6i and the piston draws airinto the oil pump cylinder during the last half of the intake stroke,and no oil is removed from the chamber.

Maximum delivery Rotation of the sleeve 54 through 90 degrees in KMinimum 'delivery Rotation of sleeve 54y through 180 degrees from theposition of Fig. 4 moves the piston its full stroke toward the left andthe operation is as follows:

The rst quarter revolution applies suction to the same, a cam on saidpiston, a sleeve providthe exhaust port 6 I and only air is drawn intothe cylinder for the first half of the suction stroke.

The second quarter revolution applies suction to the inlet port 38, andthe remaining half of the suction stroke draws oil from chamber 31, withthe result that the cylinder contains half oil and half air at the endof the suction stroke.

The third quarter revolution applies pressure to inlet port 38, but thegreater portion of the oil has reached the lower side of the cylinder,therefore the iirst half of the piston delivery stroke returns the airand possibly some of the oil to chamber 31.

The fourth quarter revolution applies pressure to the exhaust port 6 land the oil remaining in the cylinder, which is substantially one-halfof the cylinder displacement, is delivered to chamber 20.

In the modification illustrated in Fig. 6, the outlet port 1I is notcontrolled by piston movement but is placed somewhat beyond the end ofthe stroke and is provided with a check valve 12 for preventing thereturn of oil to the cylinder.

In this form of the invention the operation is quite similar to the formpreviously described, except that regulation of the quantity of oilpumped is controlled entirely by adjusting the position of slot 63 withreference to the inlet port 38.

While certain embodiments of the invention have been illustrated anddescribed, it is understood that this showing and description areillustrative only and the invention is not regarded as limited to theform shown and described, or otherl wise, except by the terms of thefollowing claims.

of said piston during rotation thereof, and means for manually rotatingthe sleeve from the exterior of the housing to adjust the delivery ofthe pump.

2. In a pump thecombination of a housing, a cylinder therein havinginlet and outlet ports, a piston insaid cylinder controlling said portsa gear surrounding said piston and having a feathered connection withsaid piston for rotating ing a bearing for said piston; means securedtothe sleeve and coacting with the cam for reciprocating said piston,and means for manually rotating the sleeve from the exterior of thehousing.

3. In a pump the combination of a housing, a cylinder therein havingaligned inlet and outlet` ports, a piston in said cylinder having a slotfor controlling said ports, a gear concentric with the piston and havinga feathered connection with said piston for rotating the same, a sleeveabutting said gear and providing a bearing for said piston, a cam onsaid piston, means secured tol ,said sleeve and-coacting with the camfor reciprocating said piston, means for manually rotating the sleevefrom the exterior of the housing, and

with,a piston having a slidable driving connec- I ing within said groovefor causing reciprocation 70 means for restraining the sleeve againstrotation. Y

tion with said worm gear and arranged to 'control said ports, spaced cammeans on said piston forming a groove therebetween, a sleeve concentricwith said piston rotatably mounted in said housing, means on said sleeveprojecting into said groove, and means for restraining rotation of saidsleeve.

5. In a pump the combination of a housing. a cylinder therein havinginlet and outlet ports, a rotatable worm, a. worm gear meshingtherewith, a piston having a slidable driving connection with said wormgear and arranged to control said ports, spaced cam means on said pistonforming a groove therebetween, a sleeve concentric with said pistonrotatably mounted in said housing, said sleeve having a reduced portionforming a bearing for said piston, means on said sleeve projecting intosaid groove, and means for restraining rotation of said sleeve. v

6. In a pump the combination of a housing, a cylinder therein havinginlet and outlet ports, a rotatable Worm, a worm gear meshing therewith,a piston having a slidable driving connection with said worm gear andarranged to control said ports, spaced cam means on said piston forminga parallel sided groove therebetween, a sleeve concentric with-saidpiston" rotatably mounted in said housing, a pin secured to said sleeveprosaid s1eeve.

7. In a pump the combination of a housing,

l a cylinder therein having inlet and outlet ports.

a groove4 therebetween, a sleeve'concentric with said piston rotatablymounted in said housing and abutting said worm gear, said sleeve havinga l reduced portion forming a bearing for said piston,

a pin secured to said sleeve-projecting into said groove, and means 'forrestraining rotation of said sleeve.

8. In a pump the combination of a housing, a horizontal cylindertherein` having,vertically arranged inlet and exhaust ports, said inletport being arranged above said exhaust port, a liquid reservoir` abovesaid inlet port and in communication therewith, an air chamber below andin communication with said exhaust port having a volume greater than thecylinder displacement of the pump, a piston in said cylinder controllingsaid ports, means for'rotating said piston during the reclprocationthereof, cam means secured to the piston or reciprocating the same. asleeve providing a bearing for said piston, a cam follower secured tothe sleeve and coacting with said said sleeve.

DAVID GREGG.

